Long time landlord here. You’re screwed.
By letting them get weeks behind in paying rent, they now have even less incentive to pay up. If you give them a break with a rent reduction, you are showing weakness, and they will soon be back to you for more favors. The time to negotiate was as soon as their rent did not come within the (presumably) five-day grace period. At that time you could have traded, say, a 7-day move out period for some cash immediately & a release from the remaining time in the lease (or month, in the case of month-to-month rental). Just get it in writing and this will suffice to modify your existing rental agreement. Then no need to serve a 3-day notice, just go right to unlawful detainer at end of 7 days. Warn them on day 6 you are going to do this.
Every time I’ve shown mercy in the past, I’ve regretted it. But I’ll probably do it again because I’m a slow learner.
